improved Sliding-Rod Eudiomeler mid of the Volumescope. 1 77 



Let it be imagined that the relative weights of the gaseous 

 mixture in question, of the oxygen gas added to it, and of the 

 carbonic acid produced, have been calculated by multiplying 

 their respective quantities, as ascertained by the eudiometer, 

 by their specific gravities. 



Since a mixture of carbonic oxide and bihydroguret of car- 

 bon, by combustion with an excess of oxygen, must be wholly 

 converted into water and carbonic acid, and since the carbonic 

 acid is entirely absorbed by lime-water, it follows that the re- 

 sidual gas must be the unconsumed portion of the oxygen gas 

 added to the mixture. Deducting this residual oxygen from 

 the whole quantity of this gas employed, the remainder is the 

 quantity consumed. The weight of the oxygen consumed added 

 to the weight of the gaseous mixture must constitute the whole 

 weight of the products, consisting, according to the premises, 

 of water and carbonic acid only, and deducting the latter, the 

 remainder will be the whole weight of the water generated. 

 Of this, agreeably to the table of equivalents, -Sths must be 

 oxygen, and ith hydrogen. 



And since the ratio of the carbon to the oxygen, in carbonic 

 acid, is as 75 to 200, //jths or j^ths of the weight of the acid 

 produced will be carbon, and fyfths or j^ths oxygen. If we 

 add, therefore, §ths of the weight of the water to j^ths of 

 that of the acid, we shall have the weight of all the oxygen in 

 the products. If from the weight thus ascertained, we deduct 

 that of all the oxygen gas consumed, the remainder will be 

 the weight of oxygen in the mixture before the oxygen gas was 

 added. This portion of oxygen is that which entered into the 

 composition of the carbonic oxide, and must, agreeably to the 

 table of equivalents, have been to the carbon in union with it, 

 as 4- to 3. Deducting the weight of the carbon, thus ascer- 

 tained to exist in the carbonic oxide, from that in the car- 

 bonic acid, as above stated, the remainder will be the weight of 

 carbon in the carburetted hydrogen. 



The rule may be thus briefly expressed. 

 From the sum of the weights of the gaseous mixture, and 

 oxygen gas consumed, deduct the carbonic acid generated. 

 To tjdis of die remainder, add ^",ths of the weight ol the car- 

 bonic acid, and deduct the weight of oxygen consumed. The 

 remainder will be the oxygen of the oxide. The carbon \n it 

 will be one-fourth less, and this carbon deducted from -,^fths 

 of the wciglit of die carbonic acid will give the weight of the 

 carbon united to the hydrogen *. When 



' The problem may lie stated algebraically as follows: — 

 Let M be the wei;^ht of the j;ascous mixture. 

 O, of tlie oxyf;eii gas conMiiiieci. 

 C, of the carbonic acid gcneratcJ and absorbed. 

 N.S. Vol. G. No. 33. Sept. 1829. 2 A Then 



